The OLED display technology has become the next generation of display technology with broad prospect for development due to the advantages of light weight, thin profile, wide viewing angle, autoluminescence, continuous and adjustable luminous color, low cost, rapid response speed, low power consumption, low driving voltage, wide operating temperature range, simple manufacturing technique, high luminous efficiency, flexible display, etc.
Researches have indicated that components such as moisture and oxygen in the air have large influence on the service life of OLED devices in OLED displays. The reasons include that: in the operating process of an OLED device, electrons must be injected from a cathode; the work function of the cathode is required to be the lower the better; but the cathode is generally made from a metallic material such as aluminum, magnesium or calcium, has active chemical properties, and tends to react with penetrated moisture and oxygen; in addition, moisture and oxygen also tends to undergo chemical reaction with a hole transport layer (HTL) and an electron transport layer (ETL) of the OLED device, and the reactions will result in the failure of the OLED device. Therefore, if the OLED device is effectively encapsulated, so that functional layers of the OLED device can be fully isolated from the components such as moisture and oxygen in the air, and hence the service life of the OLED device can be greatly prolonged, and consequently the service life of the OLED display can be prolonged.
The technical problem to be solved is to improve the moisture and oxygen resistance of the OLED device.